I. Field of the Invention
The present invention is directed generally to an apparatus and method for voltage controlled oscillation and, more particularly, to a multiple band voltage controlled oscillator using impedance scaling, and a method of providing multiple bands for a voltage controlled oscillator.
II. Description of the Background
Mobile telephone receivers typically require the use of a voltage controlled oscillator (VCO) with a specific center frequency in order to process incoming signals. In mobile telephones that are adapted to operate in multiple modes, separate voltage controlled oscillator circuits, each of which has a center frequency associated with one of the modes, are typically required to be present in the telephones in order to process received signals in the multiple modes.
The use of multiple VCO circuits in multiple mode telephones increases the number of components required to implement such devices, and such circuits occupy valuable space on the circuit boards used for implementing the telephone. It would therefore be desirable to eliminate the need for multiple, separate VCO's in multiple mode phones.